In a lid opening/closing apparatus of an electronic device according to the present invention, a lid is supported on a housing through a slide type pivot mechanism, and can reciprocate among a fully closed position, a slide position, and a fully open position. The slide type pivot mechanism comprises: an axis part projecting from the base end part of the lid; an arm plate part formed on the housing; an engagement receiving part formed on the arm plate part and to be engaged with the axis part of the lid; a bearing part formed on the arm plate part and supporting the axis part of the lid rotatably; and a holding part formed on the housing, holding the axis part of the lid between the holding part and the arm plate part, and allowing the axis part to slide. The arm plate part is elastically deformable.